Communications and Signals Design for Wireless Power Transmission

Abstract

Abstract-Radiative wireless power transfer (WPT) is a promising technology to provide cost-effective and real-time power supplies to wireless devices. Although radiative WPT shares many similar characteristics with the extensively studied wireless information transfer or communication, they also differ significantly in terms of design objectives, transmitter/receiver architectures and hardware constraints, etc. In this article, we first give an overview on the various WPT technologies, the historical development of the radiative WPT technology and the main challenges in designing contemporary radiative WPT systems. Then, we focus on discussing the new communication and signal processing techniques that can be applied to tackle these challenges. Topics discussed include energy harvester modeling, energy beamforming for WPT, channel acquisition, power region characterization in multi-user WPT, waveform design with linear and non-linear energy receiver model, safety and health issues of WPT, massive MIMO (multiple-input multiple-output) and millimeter wave (mmWave) enabled WPT, wireless charging control, and wireless power and communication systems co-design. We also point out directions that are promising for future research.Index Terms-Wireless power transfer, energy beamforming, channel estimation and feedback, power region, non-linear energy harvesting model, waveform design.

Large-Scale Multiantenna Multisine Wireless Power Transfer

“…a 2nd-order truncation model [11], [13], [15] which is the term in (10) Table II compares the computational efficiency for SU WPT and the reversed GP-based waveform optimization [13]. To draw the comparison, the stopping criteria of SU WPT and the reserved GP [13] are designed as the relative gap between the v out obtained in adjacent iterations being less than a threshold 8 …”

“…Although most off-the-shelf rectifier models in the context of microwave theory are able to provide insights into the accurate rectification process, non-closed forms or highly complex structures in these models [9], [10] make it hard to derive efficient algorithms for WPT. By contrast, [11] built a simplified (but inaccurate [8], [12], [13]) model by truncating the Taylor expansion of the Shockley diode equation to the 2nd-order term, where the rectenna DC output current is linearly proportional to the average incident RF power. This model is referred to as a linear model.…”

“…Nevertheless, the linear model may not properly describe the rectenna behaviour. In the scenario where multiple frequency components can be utilized for WPT, the linear model favours a waveform strategy where the transmit power is allocated to a single frequency component [8], [13]. Unfortunately, this contradicts experimental results that show the benefits of a power allocation over multiple frequency components to boost the RF-to-DC conversion efficiency [2]- [5].…”

“…It is shown that the linear model favours narrowband transmission, while the nonlinear model favours a power allocation over multiple frequencies. The nonlinear model leads to a completely different spectrum usage compared to the linear model [8], [13].…”

Maximization of Throughput in Wireless Powered Communication Networks

“…Yong Zeng, Bruno Clerckx, and Rui Zhang et al [19] Communications and Signals Design for Wireless Power Transmission. The study of this paper conclude that an various wireless power transfer (WPT) technology.…”